Epidemiology and Infection

Original Papers

Gastrointestinal pathogens

Clam-associated vibriosis, USA, 1988–2010

R. B. SLAYTONa1a2 c1, A. E. NEWTONa2, A. DEPAOLAa3, J. L. JONESa3 and B. E. MAHONa2

a1 Epidemic Intelligence Service Officer, Centers for Disease Control and Prevention, Atlanta, GA, USA

a2 Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

a3 U.S. Food and Drug Administration, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, AL, USA


Infections with Vibrio spp. have frequently been associated with consumption of bivalve molluscs, especially oysters, but illness associated with clams has also been well documented. We describe the 2312 domestically acquired foodborne Vibrio infections reported to the Cholera and Other Vibrio Illness Surveillance system from 1988 to 2010. Clams were associated with at least 4% (93 persons, ‘only clams’) and possibly as many as 24% (556 persons, ‘any clams’) of foodborne cases. Of those who consumed ‘only clams’, 77% of infections were caused by V. parahaemolyticus. Clam-associated illnesses were generally similar to those associated with other seafood consumption. Clams associated with these illnesses were most frequently harvested from the Atlantic coastal states and eaten raw. Our study describes the contribution of clams to the overall burden of foodborne vibriosis and indicates that a comprehensive programme to prevent foodborne vibriosis need to address the risks associated with clams.

(Received April 09 2013)

(Revised June 19 2013)

(Accepted July 09 2013)

(Online publication August 07 2013)

Key words

  • Clams;
  • epidemiology;
  • shellfish;
  • Vibrionaceae;
  • vulnificus


c1 Author for correspondence: Dr R. B. Slayton, U.S. Centers for Disease Control and Prevention, 1600 Clifton Road, MS A-31, Atlanta, GA 303 33 USA. (Email: via3@cdc.gov)